How accurate is the weighing?
We size the scales, feeders and gates to the figures in your specification. A recent tender asked for fly ash within 1.5 % and reagent and water within 1 %.
Equipment / Dosing and weighing
Dosing and weighing
Each ingredient is weighed on its own scale, then released into the mixer as one batch. Powders in weigh hoppers on load cells, reagent and water in liquid scales, all run from a recipe on the PLC.
A stabilized batch is only as good as the ratio that went into it.
Reagent is dosed as a share of the ash weight, so the ash has to be weighed first, and weighed right. Scales, feeders and the recipe are designed together with the mixer's batch size and cycle time.
How a batch is weighed
From silo to mixer
- FeedScrews or rotary valves fill each weigh hopper from its silo, on variable speed where the rate matters.
- Weigh the powdersAsh and cement are weighed in their own hoppers on load cells, each with a feed inlet and a dust connection.
- Make up the reagentChelating agent is diluted in its own tank with an agitator, then pumped by a corrosion-resistant pump into the reagent scale.
- Weigh the liquidsReagent and water are weighed electronically to the ratio set for the ash. The reagent drops into the water scale, and both go into the mixer together.
- Release and recordThe scales discharge into the mixer. The PLC logs every batch, and the records can be searched and exported.
What goes into it
Six parts
- 01
Weigh hoppers
Carbon steel, primed inside against corrosion, with a discharge gate and a dust connection. Loss-in-weight versions where a feed rate has to be held.
Examples: fly ash 1.5 m³ · cement 0.5 m³ - 02
Liquid scales
304 stainless hoppers with a pneumatic discharge valve, for reagent solution and water.
Examples: 0.4 m³ solution scale · 45 L reagent hopper on a compact station - 03
Reagent make-up
A dilution tank with agitator and level indicator, a storage tank sized for several days, and a corrosion-resistant pump.
Example: 2 m³ dilution tank · 5 m³ storage, five days' stock at a 5 % dose - 04
Feeders
Variable-speed weighing screws and rotary valves under silos and buffer hoppers. Both are made in our workshop.
Examples: weighing screw 2 t/h on a VFD · rotary valves 300 × 300 and 400 × 400 mm - 05
Load cells and controls
Load cells from Mettler-Toledo or an equivalent brand. PLC and touch screen with recipes, alarms and batch history; automatic, semi-automatic and manual modes; DCS connection available.
Examples: 1000 kg and 500 kg load cells · Siemens S7-1500 - 06
Heat tracing
Where the ash has to stay hot and dry, scales, screws and valves get electric heat tracing and insulation.
Example: weighing screw traced to 170 °C
How accurate? A recent tender asked for fly ash within 1.5 % and reagent and water within 1 %. We size the scales, feeders and gates to the figures in your specification. For a ton or two of ash a day, a compact station can weigh by hand on a platform scale.
On site
Questions buyers ask
FAQ
Which load cells and controls do you use?
Load cells from Mettler-Toledo or an equivalent brand, and a PLC with a touch screen, for example Siemens S7-1500, with recipes, alarms, batch history and automatic, semi-automatic and manual modes.
Are batch records kept?
Yes. The PLC logs every batch, and the records can be searched and exported.
Our ash is hot and picks up moisture. Is that a problem?
Scales, screws and valves get electric heat tracing and insulation where the ash has to stay hot and dry, for example tracing to 170 °C.
We only treat a ton or two a day. Is a full batching system needed?
No. For small plants a compact station can weigh by hand on a platform scale.
Who sets the recipe?
You or your process designer. We weigh and dose to that recipe; whether the product passes its test depends on the recipe and the ash.
Next step
Tell us these
- The ingredientsEach powder and liquid, and how each one arrives: silo, bulk bag or drum.
- The recipeThe ratios, and how tightly each one must be held.
- Batch and rateBatch size or mixer size, and batches an hour.
- ControlsStandalone, or tied into a plant DCS.
Where we draw the line
- The recipe itself
- We weigh and dose to your recipe. Setting the recipe, and whether the product passes leaching tests, stays with you or your process designer.
- Combustible powders
- Not without an explosion-risk assessment.